Will lower SAT Subject Scores Affect Admissions?

Hi, I’m currently a sophomore in my 4th quarter.

Freshman year I took the Biology E/M Subject Test and scored a 660 on it, which placed me only in the 57th percentile. I took multiple practice tests before hand and scored anywhere from 720-760 on them, and therefore decided to send my scores to 4 colleges (Cornell, UCLA, Harvard, and Syracuse).
The score was sent before I received it, and I was greatly disappointed upon receiving a 660 as I thought that I had done much better.

This past October, I took the PSAT and scored a 1370 on it, and I plan to retake it again my junior year aiming for a higher score. I also plan to take the World History Subject Test in June and the Chemistry Subject Test in August, and am hoping for a 750+ on those. I currently have a 4.0 unweighted GPA and participate in extracurriculars such as Speech and Debate, Student Council (Treasurer), Varsity Dance Team, and a Current Events Club, and I am planning to start a Model United Nations Club for the upcoming school year.

Will my low score on the Bio SAT II negatively affect selective colleges (Ivies, B.C., Northeastern, etc.)? If so, can I reverse these negative effects by retaking the test and getting a higher score?

If the college requires Subject Tests, then yes, it can negatively impact your application. If they do not require them, then no.

If you score higher on WH and chem, then the question is moot, since even schools that require them will look at your highest 2 (assuming none of your targeted colleges require 3).